In grain sorghum this week we observed that sugarcane aphid populations did not substantially decrease and were not affected despite the recent hard rains we received. Last week I observed heavy sugarcane aphid infestations in the panicle and upon inspecting them after the rain I observed that they were not affected and that populations had continued to increase.
Heavy sugarcane aphid populations in Hidalgo and Cameron County still persist in many areas. In Willacy County there are some lighter sugarcane aphid populations but heavy infestations were reported in Sebastian right on the county line in that area. We are still observing high numbers of alates (winged females) in grain sorghum and noticed that they are continuing to reproduce and disperse after the rains.
In recent developments this week we observed that sugarcane aphids are reproducing on corn and in sugarcane. It is not definite yet if their reproduction in corn will be prevalent, but in sugarcane they seem to be better established. Observations are being conducted and monitored in both corn and sugarcane, with much concern for sugarcane since it is an established crop all year long. Sugarcane aphids are known to be better vectors for viruses and are known for transmitting the yellow leaf virus in sugarcane.
Please inspect sorghum fields as the sugarcane aphids can populate rapidly. You can look for sugarcane aphids by looking at the field edge at the bottom stalks or look under the underside of the flag leaf for signs of infestation. You may notice honeydew or sooty mold on your stalks starting at the lower leaves; this is an indication of high sugarcane aphid populations.
You will also notice a slight glistening on the leaves, this is the honeydew deposited by the sugarcane aphids feeding that then falls onto the lower leaf, so you will want to inspect the one above under that leaf. Sugarcane aphids populate in much greater numbers than that of the yellow sugarcane aphid and are a lighter yellow in color.
A meeting to discuss the new sugarcane aphid infestation in grain sorghum will be held on Tuesday, May 20, 2014 at the Texas A&M Research & Extension Center in Weslaco. The meeting begins at 9:00 a.m. and is scheduled to last about one hour. One TDA CEU will be available. Dr. Raul Villanueva, Extension Entomologist and I, Danielle Sekula-Ortiz, Extension IPM Agent will present information about the sugarcane aphid and will conclude the meeting with a visit to an infested sorghum field to help show how to identify the sugarcane aphid in the field.